Liu Bei, Sun Jianhua, Lei Xiaoqin, Zhu Zhongqiao, Pei Cheng, Qin Li
Department of Ophthalmology, the First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
J Biosci. 2017 Dec;42(4):575-584. doi: 10.1007/s12038-017-9709-2.
The pathological development of lens epithelial cells (LECs) leads to posterior capsular opacification (PCO). This study was undertaken to investigate the effects of microRNA-486-5p (miR-486-5p) on TGF-β2-induced proliferation, invasion and epithelial-mesenchymal transition (EMT) in the lens epithelial cell line SRA01/04, and to explore the underlying molecular mechanisms. The expression of miR-486-5p in TGF-β2-induced SRA01/04 cells was down-regulated, and the expression of Smad2, p-Smad2 and p-Smad3 was up-regulated. A dual-luciferase reporter assay revealed that miR-486-5p directly targets the 30'-UTR of Smad2. MiR-486-5p mimic transfection markedly down-regulated the expression levels of Smad2, thus inhibiting the expression of p-Smad2 and p-Smad3. MiR-486-5p overexpression in SRA01/04 cells markedly suppressed TGF-β2-induced proliferation and invasion, inhibited protein expression of CDK2 and CDK4, down-regulated fibronectin, α-SMA and vimentin and up-regulated E-cadherin; these effects were partly reversed by Smad2 overexpression. In short, these data show that miR-486-5p overexpression can inhibit TGF-β2-induced proliferation, invasion and EMT in SRA01/04 cells by repressing Smad2/Smad3 signalling, implying that miR-486-5p may be an effective target to interfere in the progression of PCO.
晶状体上皮细胞（LECs）的病理发展会导致后囊膜混浊（PCO）。本研究旨在探讨微小RNA-486-5p（miR-486-5p）对转化生长因子-β2（TGF-β2）诱导的晶状体上皮细胞系SRA01/04增殖、侵袭及上皮-间质转化（EMT）的影响，并探究其潜在分子机制。在TGF-β2诱导的SRA01/04细胞中，miR-486-5p的表达下调，而Smad2、磷酸化Smad2（p-Smad2）和磷酸化Smad3（p-Smad3）的表达上调。双荧光素酶报告基因检测显示，miR-486-5p直接靶向Smad2的3'-非翻译区（3'-UTR）。转染miR-486-5p模拟物可显著下调Smad2的表达水平，从而降低p-Smad2和p-Smad3的表达。在SRA01/04细胞中过表达miR-486-5p可显著抑制TGF-β2诱导的增殖和侵袭，抑制细胞周期蛋白依赖性激酶2（CDK2）和细胞周期蛋白依赖性激酶4（CDK4）的蛋白表达，下调纤连蛋白、α-平滑肌肌动蛋白（α-SMA）和波形蛋白的表达，并上调上皮钙黏蛋白（E-cadherin）的表达；Smad2过表达可部分逆转这些作用。简而言之，这些数据表明，miR-486-5p过表达可通过抑制Smad2/Smad3信号通路来抑制TGF-β2诱导的SRA01/04细胞增殖、侵袭及EMT，这意味着miR-486-5p可能是干预PCO进展的有效靶点。
